Marlin's Special Investigations, Inc.MARLIN’S SPECIAL INVESTIGATIONS, INC. (MSI) Cedar Rapids, IACedar Rapids, IA 52410MARLIN’S SPECIAL INVESTIGATIONS, INC. (MSI), an Iowa based corporation, provides a wide range of services to attorneys, businesses and individual clients. All matters are kept confidential. Our investigators are highly skilled, licensed, bonded and insured. The State of Iowa requires that all private investigators be licensed by the Iowa Department of Public Safety